A phreatophyte is a deep-

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

that obtains a significant portion of the water that it needs from the

phreatic zone The phreatic zone, saturated zone, or zone of saturation, is the part of an aquifer, below the water table, in which relatively all pores and fractures are saturated with water. Above the water table is the unsaturated or vadose zone The v ...

(zone of saturation) or the capillary fringe above the phreatic zone. Phreatophytes are plants that are supplied with surface water and often have their roots constantly in touch with moisture. A phreatophyte is one that absorbs its water from a constant source on the ground. They can usually be found along streams where there is a steady flow of surface or groundwater in areas where the water table is near the surface. Phreatophytes live in areas with standing or running water, in arid areas and along the riverbeds and areas, apparently dry, where the

water table The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated. T ...

is very shallow and near the surface. These plants have very deep roots that are able to reach the water table. Phreatophytes are not only characteristic of arid or desert zones, but also of wetlands,

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s, depressions that hold water and

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...

. In the wetlands, ecological classification does not provide a special classification, since in this case, most of the plants in the regions of high rainfall can deepen their roots to the top of the capillary fringe immediately above the water table, and function well as a phreatophyte. In this case they receive the label of

mesophytic Mesophytes are terrestrial plants which are neither adapted to particularly dry nor particularly wet environments. An example of a mesophytic habitat would be a rural temperate meadow, which might contain goldenrod, clover, oxeye daisy, and ''Rosa m ...

. Phreatophytic artificial extensions, manmade, are used as a method to purify

greywater Greywater (or grey water, sullage, also spelled gray water in the United States) refers to domestic wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater fro ...

Biological value

They are plants of great ecological value, fast growing pioneers and highly resistant to disease. They make excellent fodder for livestock and provide nesting areas and shelter for fauna. They are used as fuel, cheap construction material, and basketry. Many of the plants grow in degraded waters, salty or saline, that are useless for agriculture. Phreatophyte plants help to purify these waters and their roots fix heavy metals with a bacterial filter. For example, it is estimated that the total annual groundwater phreatophytes consumed in the western U.S. alone is about 30,000 hm³ Phreatophytes are indicators of potable groundwater. Phreatophytes can be differentiated into plant communities by the length of their root, as they extend more or less deeply into the aquifer. Meinzer Studies. O.E. (1927) and Robinson, T.W. (1958) on vascular plants in the arid western U.S., set up certain general types of indicator species, according to level of minimum depth of the water table at which water was at the maximum suction RO. Some phreatophytes have a low tolerance for

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

, indicating freshwater. This can be a valuable guide to the location of drinking and agricultural water in arid and semiarid areas. Examples of phreatophytes include ''

Welwitschia ''Welwitschia'' is a monotypic gymnosperm genus, comprising solely the distinctive ''Welwitschia mirabilis'', endemic to the Namib desert within Namibia and Angola. ''Welwitschia'' is the only living genus of the family Welwitschiaceae and orde ...

'' and mesquite: ''

Prosopis glandulosa ''Prosopis glandulosa'', commonly known as honey mesquite, is a species of small to medium-sized, thorny shrub or tree in the legume family (Fabaceae). Distribution The plant is primarily native to the Southwestern United States and Northern M ...

''. The alfalfa, or ''

Medicago sativa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as w ...

'', is a widespread phreatophyte plant of great economic value. Trees like the ash, the

alder Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...

, the

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist so ...

and the poplar are also useful in this regard. These trees generally grow in freshwater

aquifer An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteris ...

s where the water table depth is not more than ten meters. These species are found in riparian ecosystems and areas characterized by shallow

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...

, such as bottomlands. They are also present in water limited environments; for example,

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

s in the

Mediterranean climate A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

regions.

References

{{reflist Plant morphology Riparian zone Mediterranean forests, woodlands, and scrub

Biological value

See also

References